Lactose absorption and malabsorption in healthy Italian children: do the quantity of malabsorbed sugar and the small bowel transit time play roles in symptom production?

Using breath hydrogen analysis after an oral lactose load (2 g/kg; maximum 50 g), we investigated the prevalence of lactose malabsorption in 61 healthy Italian children aged 6-13 years. We also examined the relationship between symptoms and small bowel transit time and the degree of sugar malabsorption. Three of 61 subjects produced no H2 after both lactose and lactulose load and thus were eliminated at the outset. Lactose malabsorption was defined as excretion of greater than 20 ppm H2. Lactose intolerance was classified as mild (colicky pain, flatulence, abdominal distension, borborygmi) or severe (diarrhea). The frequency of lactose malabsorption in the children aged 6-8 years (group I) was 25%; in the children aged 8-11 years (group II), it was 35%, and in the children aged 11-13 years (group III) 56%. The differences in frequency between the first and the third groups were significant (p = 0.05). Three of 20 (15%) in group I, two of 20 (10%) in group II, and three of 18 (17%) in group III were classified not only as lactose malabsorbing, but also as lactose intolerant, with symptoms during and after the test. We found no difference in the small bowel transit times or in the quantities of malabsorbed lactose in symptomatic and asymptomatic malabsorbing subjects. Other factors that may play a role in symptom production are discussed.     

The Daytime Breath Hydrogen Profile in Children with Abdominal Symptoms and Diarrhoea

ABSTRACT. The daytime breath hydrogen profile (DBHP) enables the study of breath hydrogen (BH) excretion in children under normal dietary and environmental circumstances. We studied the DBHP in 43 children with abdominal pain and (or) diarrhoea in order to evaluate its use in the detection of carbohydrate malabsorption (CHM). The results were compared to those of the lactose BH test. The DBHP was abnormal in 16 patients (37%), 8 of whom also had an abnormal lactose BH test. Five other patients with an abnormal lactose BH test had a normal DBHP. In 7 out of 10 children with an abnormal DBHP, the recorded abdominal symptoms coincided with a sharp increase in BH excretion. Abnormal DBHPs were most frequently found in children with functional abdominal complaints and with giardiasis. Our findings indicate that CHM is more frequently encountered in children with abdominal symptoms than can be detected by the lactose BH test. The DBHP offers new possibilities in the investigation of gastrointestinal conditions by correlating the symptoms directly to the effect induced by CHM.     

Lactose malabsorption and intolerance in Uruguayan population by breath hydrogen test (H2)

This study of 200 Uruguayans between 0 and 86 years old was designed to determine the prevalence of lactose malabsorption. Lactose intolerance is defined as a clinical syndrome of abdominal pain, diarrhea, flatulence, and bloating after the ingestion of a standard lactose tolerance test dose (2 g of lactose per kilogram of body weight or 50 g/m2 of body surface area, maximum 50 g in a 20% water solution). Lactose malabsorption refers to the state in which dietary lactose remains unhydrolyzed and subsequently unabsorbed from the gastrointestinal tract; symptoms may or may not result from lactose malabsorption. The technique of breath hydrogen (H2) was used after ingestion of 2 g/kg body weight to a maximum of 50 g in a 20% solution. There was no lactose malabsorption in children younger than 5 years old. The prevalence increases progressively after the age of 5, and in adolescence the percentage of malabsorption is similar to that in adults, who show 65% lactose malabsorption, with 25% asymptomatic and 40% intolerant. In 109 white adults, the prevalence of lactose malabsorption is 63%, with 24% asymptomatic and 39% intolerant. In 11 black adults, lactose malabsorption is 82%, with 27% asymptomatic and 55% intolerant. The difference between white and black adults is statistically significant (p less than 0.05). The H2 test is simple, reliable, noninvasive, and appropriate to study large populations.     

The daytime breath hydrogen profile in children with abdominal symptoms and diarrhoea

The daytime breath hydrogen profile (DBHP) enables the study of breath hydrogen (BH) excretion in children under normal dietary and environmental circumstances. We studied the DBHP in 43 children with abdominal pain and (or) diarrhoea in order to evaluate its use in the detection of carbohydrate malabsorption (CHM). The results were compared to those of the lactose BH test. The DBHP was abnormal in 16 patients (37%), 8 of whom also had an abnormal lactose BH test. Five other patients with an abnormal lactose BH test had a normal DBHP. In 7 out of 10 children with an abnormal DBHP, the recorded abdominal symptoms coincided with a sharp increase in BH excretion. Abnormal DBHPs were most frequently found in children with functional abdominal complaints and with giardiasis. Our findings indicate that CHM is more frequently encountered in children with abdominal symptoms than can be detected by the lactose BH test. The DBHP offers new possibilities in the investigation of gastrointestinal conditions by correlating the symptoms directly to the effect induced by CHM.     

印度尼西亚儿童牛奶摄入与乳糖吸收不良之间的关系

目的 探讨3~12岁印度尼西亚儿童牛奶摄入与乳糖吸收不良之间的关系。 方法 该研究为横断面研究。研究对象为在印度尼西亚雅加达中部随机选取的营养状况良好的174名3~12岁健康儿童,包括72名3~5岁儿童和102名6~12岁儿童。 结果 3~5岁儿童乳糖吸收不良患病率为20.8%（15/72）,6~12岁儿童乳糖吸收不良患病率为35.3%（36/102）。牛奶或乳制品摄入与乳糖吸收不良之间无显著关联性（P>0.05）。在氢呼气试验中,51例乳糖吸收不良儿童主要表现为腹泻（62%）、腹痛（52%）和恶心（5%）。 结论 3~12岁印度尼西亚儿童牛奶摄入和乳糖吸收不良无关联,这提示遗传易感性可能比乳糖摄入的适应机制更重要。     

Ampicillin vs. placebo for Yersinia pseudotuberculosis infection in children

For evaluation of the efficacy of early treatment with ampicillin on the clinical course of Yersinia pseudotuberculosis infection in children, 136 patients were randomly assigned to receive either ampicillin or placebo. Subjects were those who were diagnosed as having Kawasaki syndrome and those who satisfied three of the following four criteria: fever; rash; abdominal symptoms; and a history of ingestion of untreated drinking water. Fifty-six patients had evidence of Y. pseudotuberculosis infection bacteriologically and/or serologically. Twenty-six were assigned to placebo and 28 to ampicillin. Ampicillin therapy did not show a significant benefit in shortening the duration of fever, diarrhea and abdominal pain or in preventing rash, erythema nodosum and acute renal failure. After 5 days of treatment none of the patients in the ampicillin group excreted the organism in the stool whereas 19 (90%) of 21 in the placebo group did (P less than 0.001). Ampicillin did not show a clinical benefit but reduced the fecal excretion of the organism.     

Carbohydrate malabsorption following fruit juice ingestion in young children

We performed breath hydrogen analyses in 13 healthy children (9 to 36 months of age) and seven children (14 to 27 months of age) with chronic nonspecific diarrhea after they had ingested pear, grape, and apple juices and a 2% sorbitol solution. Excess breath H2 excretion was found in virtually all study subjects following the ingestion of either pear juice (with approximately 2% sorbitol content) or the 2% sorbitol solution, in approximately 50% of those ingesting apple juice (0.5% sorbitol), and in 25% of those ingesting grape juice (no sorbitol) (P less than .001, analysis of variance). No differences were noted between the healthy children and those with chronic nonspecific diarrhea. Forty percent of all study subjects in whom excess breath hydrogen excretion occurred also had diarrhea and abdominal cramping. Carbohydrate malabsorption appears to be frequent following the ingestion of common fruit juices and in some children may be associated with nonspecific gastrointestinal symptoms.     

Lactose and fructose malabsorption in children with recurrent abdominal pain: results of double-blinded testing

Aim: To investigate malabsorption of lactose and fructose as causes of recurrent abdominal pain (RAP). Methods: In 220 children (128 girls, mean age 8,8 [4.1–16.0] years) with RAP, hydrogen breath tests (H₂BT; abnormal if ΔH₂ > 30 ppm) were performed with lactose and fructose. Disappearance of RAP with elimination, recurrence with provocation and disappearance with re‐elimination, followed by a 6‐month pain‐free follow‐up, were considered indicative of a causal relation with RAP. For definite proof, a double‐blinded placebo‐controlled (DBPC) provocation was performed. Results: Malabsorption of lactose was found in 57 of 210, of fructose in 79 of 121 patients. Pain disappeared upon elimination in 24/38 patients with lactose malabsorption, and in 32/49 with fructose malabsorption. Open provocation with lactose and fructose was positive in 7/23 and 13/31 patients. DBPC provocation in 6/7 and 8/13 patients was negative in all. However, several children continued to report abdominal symptoms upon intake of milk or fructose. Conclusion: Lactose intolerance nor fructose intolerance could be established as causes of RAP, according to preset criteria including elimination, open provocation and DBPC provocation. However, in clinical practice, persistent feeling of intolerance in some patients should be taken seriously and could warrant extended elimination with repeated challenges.     

Hydrogen (H2) breath test following lactose loading in children with recurrent abdominal pain

To define the practical diagnostic value of H2 breath testing after lactose load in children with chronic abdominal pain, we measured end-expiratory H2 every 30 minutes for 2 hours after peroral lactose (2 g/kg body weight, Lactoscreen). H2 testing was done in 62 children (28 female, 32 male), aged between 2 and 16 years. Abdominal pain had been observed in these children for more than 2 months. Causes of abdominal pain other than lactose intolerance had been excluded. In 2 out of 62 children, H2 testing was impossible for lack of cooperation. 17 out of the remaining 60 children showed a positive test result (28.3%). In 15 patients, the rise in H2 exceeded 40 ppm, and was thus easily distinguished from a nonspecific rise (less than 25 ppm). Stool pH and Clini-test results were not correlating well with H2 findings, In 16 out of 17 children with positive H2 tests, abdominal pain had ceased on a diet free of lactose after a month. After 6 months 15 out of 17 children were symptom free. These data confirm early indication of non-invasive H2 testing in children with chronic abdominal pain.     

Breath hydrogen excretion in infants with colic.

Breath hydrogen excretion as an index of incomplete lactose absorption was measured in 118 healthy infants who were either breast fed or given a formula feed containing lactose, some of whom had colic. Infants with colic (n = 65) were selected on the basis of the mother''s report of a history of inconsolable crying lasting several hours each day. Infants in the control group (n = 53) were not reported to cry excessively by their mothers. Breath samples were collected using a face mask sampling device preprandially, and 90 and 150 minutes after the start of a feed. Normalised breath hydrogen concentrations were higher in the group with colic than in the control group at each time point. The median maximum breath hydrogen concentration in the colic group was 29 ppm, and in the control group 11 ppm. The percentage of infants with incomplete lactose absorption (breath hydrogen concentration more than 20 ppm) in the colic group was 62% compared with 32% in the control group. The clinical importance of the observed association between increased breath hydrogen excretion and infantile colic remains to be determined. Increased breath hydrogen excretion indicative of incomplete lactose absorption may be either a cause or an effect of colic in infants.     

Ineffectiveness of breath methane excretion as a diagnostic test for lactose malabsorption

BACKGROUND: In clinical and field conditions, breath gas analysis has been widely used in evaluating carbohydrate digestion. A field study was performed to determine the prevalence of lactose malabsorption in Myanmar children and to evaluate the possibility of using breath methane excretion to indicate lactose malabsorption in a field situation. METHODS: The study population consisted of 118 children aged 1 to 12 years. A hydrogen breath test after a lactose meal (2 g/kg, maximum 50 g) was used as a standard test. RESULTS: Lactose malabsorption was detected in 16.7% of children aged 1 to 2.9 years, with the prevalence increasing with age from 40.5% of those aged 3 to 5.9 years to 88.5% of those aged 6 to 8.9 years and reaching 91.7% in those aged 9 to 11.9 years. Lactose malabsorption was more prevalent when children were weaned before 4 months of age (87.2 vs. 41.1%; p < 0.01). Compared with lactose-tolerant children, those with lactose malabsorption had significantly higher concentrations of breath hydrogen excretion 60 minutes after the lactose test meal. Breath methane excretion was also significantly higher in samples at 120 minutes in children with lactose malabsorption. Breath methane excretion of greater than or equal to 2 parts per million at 180 minutes as a diagnostic test for lactose malabsorption had a sensitivity of 61.5% and a specificity of 84.6%. CONCLUSION: The breath methane test for lactose malabsorption has a lower sensitivity and specificity than the breath hydrogen test and therefore does not replace the lactose breath hydrogen test.     

Objawy hipolaktazji występujące wśród dzieci,młodzieży i studentów szkół szczecińskich

Introduction

Adult-type hypolactasia is a physiological and genetically conditioned process, which is manifested by a regular decrease of the intestinal lactase activity from childhood to adulthood. It results in an incomplete digestion process in the small intestine, which can lead to intestinal disorders, and is diagnosed as lactose intolerance (LI).

Incomplete intestinal absorption of fructose.

Intestinal D-fructose absorption in 31 children was investigated using measurements of breath hydrogen. Twenty five children had no abdominal symptoms and six had functional bowel disorders. After ingestion of fructose (2 g/kg bodyweight), 22 children (71%) showed a breath hydrogen increase of more than 10 ppm over basal values, indicating incomplete absorption: the increase averaged 53 ppm, range 12 to 250 ppm. Four of these children experienced abdominal symptoms. Three of the six children with bowel disorders showed incomplete absorption. Seven children were tested again with an equal amount of glucose, and in three of them also of galactose, added to the fructose. The mean maximum breath hydrogen increases were 5 and 10 ppm, respectively, compared with 103 ppm after fructose alone. In one boy several tests were performed with various sugars; fructose was the only sugar incompletely absorbed, and the effect of glucose on fructose absorption was shown to be dependent on the amount added. It is concluded that children have a limited absorptive capacity for fructose. We speculate that the enhancing effect of glucose and galactose on fructose absorption may be due to activation of the fructose carrier. Apple juice in particular contains fructose in excess of glucose and could lead to abdominal symptoms in susceptible children.     

Late-onset hypolactasia in Hong Kong school children.

Three hundred and twenty Chinese school children aged between 6 and 19 years from six schools in Hong Kong were tested for their lactose digestion status. After an overnight fast, the children were challenged with cow's milk, 5 ml/kg bodyweight (i.e. lactose approximately 0.25 g/kg). Malabsorption was assessed by measuring hydrogen concentration from end-expiratory breath samples taken in duplicate before and at 90 and 180 minutes after the challenge. On average, 10% of the children showed an increase in breath hydrogen excretion within 3 h after the challenge, indicating malabsorption of lactose. None of the children complained of gastro-intestinal symptoms or showed any clinical sign of intolerance to the milk. The number of malabsorbers increased significantly (p less than 0.001) with age, starting at about 3% at the age of 8 and reaching about 27% at the age of 18 years. The sharpest rise occurred between 14 and 15 years. It is concluded that, despite the high prevalence of hypolactasia, Hong Kong Chinese children can consume normal amounts of milk without developing any untoward clinical symptom or sign.     

Lactose maldigestion: increased age-related prevalence in institutionalized children

A study was performed to determine whether the age-related prevalence of lactose maldigestion is increased in healthy institutionalized children. Previous malnutrition did not exclude children from study. The control children had no prior history of malnutrition or hospital admissions for diarrhea. The anthropometric comparison showed the institutionalized children to be shorter and lighter than the controls, but they were of normal weight by stature, suggesting a normal recent nutritional state. Fasting breath hydrogen tests were performed following an oral dose of lactose 1 g/kg, given as a 10% solution. A rise of breath hydrogen of greater than or equal to 20 ppm was considered to indicate lactose maldigestion. Twenty-two of 44 controls and 39 of 49 study children were lactose maldigesters (p less than 0.01). The control children showed an age-related increase in the prevalence of lactose maldigestion, from 31.6% at age less than 5 years to 75% at age greater than 9 years. The institutionalized children, by comparison had an increased prevalence of 78.8% in the group under 5 years of age (p = 0.002). Equally high prevalence rates were found at all ages tested. At follow-up, lactose maldigestion was persistent in the majority of the study children. This had no nutritional impact despite a regular milk intake. The distinction between acquired and primary lactose maldigestion is of no practical significance in these children.     

Abdominal pain associated with lactose ingestion in children with lactose intolerance

The causal relationship between lactose ingestion and gastrointestinal symptoms is questionable. The aim of this study was to assess symptoms associated with milk ingestion in children with lactose maldigestion. Thirty children (11 males) age 3 to 17 years with lactose maldigestion were studied. In a double-blind, crossover design, subjects ingested 240 mL daily of either lactose-hydrolyzed or lactose-containing milk for 14 days. Diaries were kept daily that recorded diet, medication use, and symptoms. There was a significant increase in abdominal pain experienced by study participants during the lactose ingestion period when compared to the lactose-free period. We conclude that ingestion of 12 g of lactose daily is associated with increased abdominal pain in susceptible children with lactose maldigestion. A trial of dietary lactose restriction may be beneficial in reducing abdominal pain in children with lactose maldigestion.     

Bacterial contamination of the small intestine as an important cause of chronic diarrhea and abdominal pain: diagnosis by breath hydrogen test

Unsuspected bacterial contamination of the small intestine was indicated by breath hydrogen testing in nine patients aged 2 to 34 months during physical examinations for chronic diarrhea and abdominal pain. Elevated bacterial counts of questionable significance were found in duodenal aspirates before and after antibiotic treatment. There was no evidence of bile salt deconjugation or structural changes in the small intestine by light or electron microscopy. This may indicate that the site of colonization is distal to the biopsy site. Breath testing indicated lactose malabsorption in all patients, and four of five patients tested also malabsorbed sucrose. Duodenal disaccharidase levels in all patients were within the normal ranges, but in eight patients the lactase-sucrase ratio was greatly elevated (0.80 +/- 0.36; normal less than 0.45). Dietary restriction alone did not cause complete cessation of symptoms, whereas all patients responded dramatically to oral antibiotic therapy. When patients were well, the lactase-sucrase ratio had returned to normal in those tested, and all nine had normal lactose and lactulose breath hydrogen tests. Unsuspected bacterial contamination of the small intestine, which is easily detected using the breath hydrogen test, may be more commonly associated with chronic diarrhea in children than has been previously realized. In such cases, therapy should be directed at removing the contamination.     

Lactose malabsorption during gastroenteritis, assessed by the hydrogen breath test

Thirty-eight infants and young children with gastroenteritis were investigated for lactose malabsorption. Each of them was given an oral lactose load of either 0.5 g/kg or 2 g/kg after which breath hydrogen excretion was measured, and each was observed to see if he had clinical symptoms of lactose intolerance. Only one patient, given 2 g/kg lactose, had clinical intolerance. His breath hydrogen excretion however was negative. Three of 18 patients given 0.5 g/kg lactose had positive breath hydrogen tests. None of these was symptomatic. Lactose intolerance in gastroenteritis was rare in our study, and the hydrogen breath test was not an appropriate technique for detecting it.     

儿童荨麻疹与成人荨麻疹患者临床特征的比较分析

目的探讨儿童荨麻疹和成人荨麻疹临床特征的差异,为儿童荨麻疹的病因、病情评估及治疗提供参考依据。方法收集2013年1月至2017年5月在中南大学湘雅医院皮肤科就诊的2 411例荨麻疹患者资料进行社会人口学特征分析,并对其中获得完整随访资料的740例荨麻疹患者进行儿童(68例)和成人(672例)荨麻疹临床特征的比较分析。结果儿童组中急性荨麻疹314例,占76.4%(314/411),而成人组以慢性自发性荨麻疹为主(44.8%,896/2 000)。儿童急性荨麻疹以感染为病因者占41%(16/39)。儿童急性荨麻疹的伴随症状以腹痛/腹泻为主(44%,17/39),而成人急性荨麻疹以胸闷/气促为主要伴随症状(32%,11/34)。儿童组慢性荨麻疹治疗前后疾病严重度评分低于成人组(P0.05);儿童组第二代抗组胺药治疗有效率高于成人组(82.1%vs 62.2%,P0.05)。儿童组荨麻疹个人史及家族史阳性率均高于成人组(P0.05)。结论儿童荨麻疹中以急性荨麻疹多见,主要伴随症状为腹痛/腹泻,与成人不同。儿童慢性荨麻疹的疗效较成人佳。儿童急性荨麻疹患者常见病因为感染。具有特应性体质儿童可能易患荨麻疹。     

Lactose malabsorption and recurrent abdominal pain in Italian children

The role of lactose malabsorption (LM) was investigated in 32 children (mean age 8.13 +/- 2.46 years) with recurrent abdominal pain (RAP). LM was detected in 75% of them by a lactose breath hydrogen test (LBHT) after a 2-g/kg (max 50-g) load. Of the 18 malabsorbers who participated in a 3-month lactose-free diet (LFD), 14 were judged "improved" and reported lower pain frequency (p less than 0.001). The malabsorbers who improved versus the not improved had comparable past lactose ingestion but were distinguishable on the basis of their lactose absorption capacity (0.36 vs. 0.81 g/kg; p less than 0.01), as subsequently determined by multiple LBHTs with 25-, 12.5-, and 6-g loads. The ratio between past lactose ingestion and lactose absorption was 1.89 in the improved and 0.55 in the not improved groups (p less than 0.01), retrospectively indicating lactose as a possible cause of the symptoms in the improved group. The reintroduction of lactose in amounts not exceeding the absorption capacity into the diet of each malabsorber who had improved with LFD caused relapse in none of the 14 subjects monitored for 2-6 months. In conclusion, LM seems an important cause of symptoms in Italian children with RAP. Assessment of the lactose absorption threshold of each subject of LBHTs provides a basis for reintroduction of "calibrated" amounts of lactose-containing foods (e.g., milk) into the diet.